Primary and secondary suspending reagents are often used in suspension polymerisation reactions, such as the suspension polymerisation of vinyl chloride. The primary suspending agent controls coalescence of the polymer particles, and therefore primarily dictates the size of the polymer particles so formed. The secondary suspending agent typically defines secondary characteristics of the polymer particles, such as particle shape and porosity. Such secondary suspending agents typically comprise partially hydrolysed vinyl acetates (with a typical degree of hydrolysis of 35 to 55 mol %). Production of the partially hydrolysed polyvinyl acetate is a two-step process involving production of the polyvinyl acetate and subsequent partial hydrolysis. There is therefore a desire to be able to create a secondary suspending agent which may function without hydrolysis.
The present invention seeks to mitigate the above-mentioned problems. Alternatively or additionally, the present invention seeks to provide an alternative and/or improved secondary suspending agent for a suspension polymerisation reaction.